The answer is state.
That is the state would be least helpful in determining whether a substance is a metal or a nonmetal. The state can only tells that a compound is liquid, gas or solid. But it can't tell whether a substance is metal or non-metal. So it is the least helpful in determining whether a compound is metal or non-metal.
Answer:
Thermal and electric conductivities.
Explanation:
Metals tends to have high thermal and electric conductivities in comparison with nonmentals.
